Engineering Questions with Answers - Multiple Choice Questions

# Distillation Design MCQ’s – Key Components of Multicomponent Distillation

1 - Question

For the light key component, Equilibrium relation is
a) yK=x
b) Kx=y
c) Depend upon trays
d) Can’t be specified

Explanation: Here Kx=y is the equilibrium relation, which does not depends upon the number of trays or the vice versa relation i.e. Kx=y representing x and y moles of gas and fluid.

2 - Question

If the fractional recovery of light key in the distillate is FR, then light key in the feed is
a) DxD= (FRD)+FxLK
b) DxD= (FRD)/FxLK
c) DxD= (FRD)FxLK
d) DxD= (FRD)

Explanation: The definition of the fractional recovery is DxD= (FRD) FxLK, while gives us the material balance on feed and distillate DxD= (FRD).

3 - Question

For multi-component systems, Underwood Equations gives
a) Minimum Reflux
b) Minimum Strip
c) Maximum Reflux
d) Minimum Trays

Explanation: Underwood Equations gives Minimum Reflux, Fenske’s equation gives minimum Trays and McCabe gives us minimum Reflux.

4 - Question

Gilliland Correlation is arranged to estimate the
a) Numbers of Stages
b) Numbers of Reboiler
c) Numbers of Feed
d) Numbers of Column

Explanation: Gilliland Correlation is arranged to estimate the Numbers of Stages at finite reflux ratio, while reboiler is only a unit piece of set.

5 - Question

Gilliland’s y intercept is given as
a) Nmin/N+1
b) N-Nmin/N+1
c) N+Nmin/N+1
d) N/N+1

Explanation: Gilliland represented correlation graphically as, N-Nmin/N+1 on y axis, where N is the number of stages.

6 - Question

Gilliland’s x intercept is given as
a) Rmin/R+1
b) R/R+1
c) Nmin/R+1
d) R-Rmin/R+1

Explanation: Gilliland represented correlation graphically as R-Rmin/R+1 on x axis, where R is the reflux ratio of the system.

7 - Question

Optimum feed-stage location, can be obtained by using
a) Gilliland correlation
b) Kirk bride correlation
c) Fenske’s correlation
d) Sorel’s correlation

Explanation: An approximate optimum feed-stage location, can be obtained by Equation of Kirk bride correlation while Gilliland correlation is used to plot intercepts.

8 - Question

For Multicomponent Mixtures Equilibria depend on ?
a) Pressure
b) Temperature
c) Humidity
d) Enthalpy

Explanation: It depends on T, which changes from stage to stage, Pressure is not the deciding criteria as it can vary from Colum to column.

9 - Question

In multicomponent distillation, the separation of components is calculated using
a) Assumed flows of species
b) Assumed flows of reflux
c) Assumed flows of Vapor
d) Assumed flows of liquid

Explanation: The number of plates above and below the feed is assumed, and the separation is calculated using assumed reflux.

10 - Question

Once the components are identified, in a multicomponent distillation they are called
a) Key Components
b) Mixed Components
c) Flow Components
d) Gain Components